Caffrey Deirdre, Miranda J Jaime, Gilman Robert H, Davila-Roman Victor G, Cabrera Lilia, Dowling Russell, Stewart Talia, Bernabe-Ortiz Antonio, Wise Robert, Leon-Velarde Fabiola, Checkley William
Division of Pulmonary and Critical Care, School of Medicine, Johns Hopkins University, 1800 Orleans St, Suite 9121, Baltimore, MD 21205, USA.
Extrem Physiol Med. 2014 Feb 1;3(1):3. doi: 10.1186/2046-7648-3-3.
We sought to determine if adult residents living at high altitude have developed sufficient adaptation to a hypoxic environment to match the functional capacity of a similar population at sea level. To test this hypothesis, we compared the 6-min walk test distance (6MWD) in 334 residents living at sea level vs. at high altitude.
We enrolled 168 healthy adults aged ≥35 years residing at sea level in Lima and 166 individuals residing at 3,825 m above sea level in Puno, Peru. Participants completed a 6-min walk test, answered a sociodemographics and clinical questionnaire, underwent spirometry, and a blood test.
Average age was 54.0 vs. 53.8 years, 48% vs. 43% were male, average height was 155 vs. 158 cm, average blood oxygen saturation was 98% vs. 90%, and average resting heart rate was 67 vs. 72 beats/min in Lima vs. Puno. In multivariable regression, participants in Puno walked 47.6 m less (95% CI -81.7 to -13.6 m; p < 0.01) than those in Lima. Other variables besides age and height that were associated with 6MWD include change in heart rate (4.0 m per beats/min increase above resting heart rate; p < 0.001) and percent body fat (-1.4 m per % increase; p = 0.02).
The 6-min walk test predicted a lowered functional capacity among Andean high altitude vs. sea level natives at their altitude of residence, which could be explained by an incomplete adaptation or a protective mechanism favoring neuro- and cardioprotection over psychomotor activity.
我们试图确定生活在高海拔地区的成年居民是否已形成对低氧环境的充分适应，以匹配海平面地区类似人群的功能能力。为验证这一假设，我们比较了334名生活在海平面地区与高海拔地区居民的6分钟步行试验距离（6MWD）。
我们招募了168名年龄≥35岁、居住在秘鲁利马海平面地区的健康成年人，以及166名居住在秘鲁普诺海拔3825米处的个体。参与者完成了6分钟步行试验，回答了社会人口统计学和临床问卷，接受了肺活量测定和血液检测。
利马和普诺参与者的平均年龄分别为54.0岁和53.8岁，男性比例分别为48%和43%，平均身高分别为155厘米和158厘米，平均血氧饱和度分别为98%和90%，静息心率分别为67次/分钟和72次/分钟。在多变量回归分析中，普诺的参与者比利马的参与者少走47.6米（95%置信区间-81.7至-13.6米；p<0.01）。除年龄和身高外，与6MWD相关的其他变量包括心率变化（静息心率以上每增加1次/分钟增加4.0米；p<0.001）和体脂百分比（每增加1%减少1.4米；p=0.02）。
6分钟步行试验预测，安第斯高海拔地区居民相对于海平面地区居民在其居住海拔高度的功能能力较低，这可能是由于适应不完全或一种有利于神经和心脏保护而非精神运动活动的保护机制所致。
